Improved device for converting motion



-l b 11; also the guide-rods ,ing two mutilated l alteinately.

tanned'` san- @stent @Wina THOMASA. MITCHELL, OF WASHINGTON, DISTRICT OF COLUMBIA.

Letters .Pate/at No. 91,555, dated June 22, 1869.

i IMPROYED-DEVICE FOR CONVERTIN G- MOTION.

had totheaccompanyfing drawings,and to the letters of reference marked thereon.

`My invention consists of certain guides, guide-blocks, and buffers, arranged as described.

In the accompanying drawingsl Figure l is a side 4View of mylinvention.

Figure 2 is a modified formpf vmy rack. y Figure 3 is a'gsectional view of myrack through .the

l line xz, fig.` 1.

Figures 4 and 5 are guide-blocks.V

In Iig. 1, the double rack Ais formed of the frame j a, to which are fastened,iu different planes, the racks B B, the' elastic buers c c, i and the connecting-rod I), by which the contrivance `may be attached to any machine of which'it shall 1 form a part.I r

Between the guiderods B-`B is the shaft E, carrypinions, meshing with the racks These pinions are formed with such a number of ,"fteeth, that dur-ing their continuous revolution, the

, rack will receive a reciprocating motion.V

The guide-rods ,B B, resting on the shaft E,are in- Y `telided to support and direct the'motiou of theframe y a. But if the frame and racks `he made in one piece,

" ,and solid,:a slt may be used, the :edges of which shall be the equivalent of the guide-bars.

y The buffers c c, striking the shaft E at each `end of be seen at Kiu sectional the stroke, prevent a strain upon the cogs of either rack or pinion at the instant of' changing motion.

,To avoid the wear of the shaft from the friction of the guide-rods, I introduce a block, similar to fig. 4 or 5, hung ou' the shaft between the guide-rods, as may view, fig. 3, in which E is the shaft; F F, the pinions'; B B, the guide-rods; b b, the racks; and a a, the frame.

For producing reciprocating' rectilinear motion, I prefer the form shown in fig. 1; but for certain purposes, I use racks of a simple or compound curvature, or any form adapted to the machine 'of which it makes part. Y

Fig. 2 is an illustration of a simple curved rack.

In order to increase the strength of the apparatus, I sometimes use four or more racks, arranged in opposite pairs, as in g. 3,'n which b H b H are the racks operated by the piuions F F.

Having thus described my invention,

I claim, and desire to secure by Letters Patent- 1. The guide-rods, forming a slot, resting on the shaft, for supporting-and directing the racks.

2. Introducing a block in the slot, or between the guide-bars, hung on the shaft, to reduce friction and cause a more smooth and even motion of the racks.

3. In combination with the above, the elastic buffers at each en d of the rack-frame, for preventing undue strain on the teeth of either racks or pinions, at

the end of stroke.

THOMAS A.. MITCHELL.

Witnesses DANIEL BREED, A. B. PAIGE. 

